HMP155 supports a 2-wire RS-485 communication. The RS-485 interface is non-isolated and offers a maximum communication rate of 19200 bits/s. There is no internal termination for the RS-485. If any termination is needed, terminate the bus at both ends. The recommended termination is R termination with 120 Ω resistors.
Typically, termination resistors are only needed when the fastest communications rate (19200 bit/s) is used for longer distances. If you use resistors, take into account the possible increase in the current consumption.